<!DOCTYPE HTML>
<html>
<head>
	<meta charset="utf-8"/>
	<style type="text/css">
   
      

     
      
      .father{
      	width: 100%;
      	height: 100px;
      	background-color:pink;
        position:relative;
      	
      }

       .son{
        width: 100%;
        height: 20px;
        background-color:yellow;
      
        position:absolute;
        bottom: 0px;
        
      }

    


	</style>
      

</head>
<body>
     <div class="father">
            <div class="son"></div>     
  

     </div>

    
    
    
      
  


</body>
</html>


